1. Field of the Invention
A dynamic roller gap setting system for a paper folder is related. Disclosed is a standard buckle folder adapted with a dynamic folding mechanism utilizing twin actuators that rapidly and reliably adjusts the rollers within the folder to receive multi-page packets of paper that vary in the number of included pages.
2. Description of the Background Art
Numerous types of buckle folders with modifications and variations exist is the mailing industry. However, the prior folders have rollers that lack the ability to automatically and rapidly adapt in a reliable manner to receive multi-page packets that essentially randomly vary in the number of pages with in a packet.
Generally, the buckle folder works by receiving a packet of pages between rollers and the packet progresses into a folding cage or gate. When the packet reaches the set stop point for the folding cage, the front edge of the packet stops even though the trailing edge of the packet is still being fed into the folder. The continuous feeding causes the packet to buckle and be forced down through the next set of folding rollers which crease the packet at a point determined by the folding gate set stop point. A control system drives the direction of rotation of the rollers. Preferably, it is this type of buckle folder or equivalent that is modified to accept the subject system.
The standard buckle folder comes with rollers that have an adjustable gap, however, the gap adjustments are very slow and prevent the rapid processing of packets with variable numbers of pages. The rollers are adjusted by a rigid linkage that comprises a screw mechanism that has a knob for setting the roller gap. Usually, a group of packets all having the same number of pages is process in bulk and then the knob is turned to set the gap for another group of packets with a different number of pages.
Specifically, U.S. Pat. No. 3,516,655 discloses a method and means for fold adjustment in a buckle chute folding machine. Variable fold lengths are generated by this apparatus, but roller spacings are virtually fixed to receive a set number of pages to fold.
U.S. Pat. No. 4,032,133 teaches a buckle folder that incorporates rollers having adjustable gaps. Adjusting screws are fastened to appropriate rollers and hand rotated to pre-select desired spacing values.
Described in U.S. Pat. No. 4,223,882 is an automatic in-line mailing system. Included in this system is a folder that receives sheets generated from a cutter utilizing a roll of forms.
A folding machine is communicated in U.S. Pat. No. 4,225,128. Similar to U.S. Pat. No. 4,032,133 above, the apparatus related here comprises a plurality of main rollers and adjustable roll combinations. Each roll may be independently adjusted by means of finger activated screw mechanisms.
U.S. Pat. No. 4,403,981 discusses a folding machine that comprises a several rollers and a cartridge that turns about an axis. This device permits semi-rigid cards to be included within the final folded packet.
Explained in U.S. Pat. No. 4,586,704 is a buckle-type sheet folder. The design of this apparatus permits different folding patterns to be generated by activating sheet stops and deflectors. A console is included in the machine that activates motors to drive the sheet stops and deflectors.
U.S. Pat. No. 4,621,966 reveals a shingle compensating device. A stack of forms is forced into an off-set (shingled) stack for delivery to a folder. Due to the off-set nature of the stack, the folder is then capable of folding the shingled stack into an aligned final version.
U.S. Pat. No. 4,843,802 discloses an inserting apparatus. Various fixed rollers are employed in the folding and inserting process.
A paper folding apparatus is presented in U.S. Pat. No. 4,944,131. Included is first signal when a normal insert is introduced between two receiving rollers (one has a fixed rotational axis and the other a movable rotational axis) and a second signal when two or more inserts are introduced between these rollers. The first signal causes the machine to halt the progress of the first insert until a second insert has been positioned in a leading fold of the first insert. The second signal stops the machine and initiates on the control panel of the machine that a double insert has occurred. A simple optical detector is attached to the movable roller and notes one of two possible positions for signaling a double insert.
U.S. Pat. No. 5,045,039 discloses a program controlled sheet folding apparatus for folding large sheets into predetermined formats. To produce a desired folding pattern, several rollers are present and the rotational directions of these rollers are controlled by a programmable means.
Described in U.S. Pat. No. 5,082,255 is a sheet processing apparatus. that has a roller that is positioned by a single screw jack drive on each end of the roller. A motor, output shaft, pulley gears, and timing belt are included in the roller width changing structure.